If a system described in terms of empty and filled states ( and •, respectively) interacts with particles M via the following reactions: (with α being a real number), then it may be described in terms of fractional statistics. On the other hand, provided that the states are identified with adsorption sites, this scheme may be used, according to the value assigned to α, for the description of adsorption–desorption phenomena such as the inhibition of empty sites by the adsorption of polyatomic molecules, multilayer adsorption, and the branched growth of dendrimers. Not only does the fractional statistical treatment reproduce the well-known Langmuir and Brunauer–Emmett–Teller isotherms for α = 0 and α = 1, but also it provides the adsorption isotherms for all other values of α. It is also shown that considered as a function of the parameter α the equilibrium isotherm undergoes a catastrophe at α = 1.